(a) Use the fact that the population was 250 million in 1990 (t=0) to formulate a logistic model for the US population. Assume the carrying capacity is 4200 million. p: (b) Determine the value ofk in your model by using the fact that the population in 2000 was 275 million. (Round your answer to eight decimal places.) (c) Use your model to predict the US population in the years 2100 and 2200. (Round your answers to the nearest whole number.) P = million in 2100 F = million in 2200 (d) Jse your model to predict the year in which the US population will exceed 350 million. :1